In Old Saybrook: Penny Lane Pub has decent food as well as drinks, Som Siam East is best Asian, Liv's Oyster Bar has best seafood. I have only had takeout from Tissa's Moroccan Market, but based on that I think eating there would be quite interesting (they have good ice cream too). Samurai is ok Japanese, but Hanami in Clinton is better. Johnny Ad's Drive in is a funky clam-shacky place but my DW prefers Lenny and Joe's in Westbrook. Taste of China in Clinton is best Chinese in the area.

Lots of other good restaurants along the shoreline, but I limited my comments to the cuisines you mentioned.